Typically, an air battery using, as a positive electrode active material, oxygen contained in air has been known. The air battery commonly includes a negative electrode, a positive electrode, and an electrolytic solution layer provided between the negative electrode and the positive electrode. For example, the positive electrode has a configuration containing carbon, whereas the negative electrode is made of a metal material such as metal lithium. Reduction reaction using oxygen is performed in the positive electrode, whereas metal ionization reaction is performed to release electrons in the negative electrode. In this manner, the air battery performs, as a whole, electric generation.
Patent Literatures 1 and 2 describe examples of the electrolytic solution layer. That is, Patent Literature 1 discloses an electrolytic solution holding layer for holding, as an electrolytic solution, a water solution of potassium chloride, sodium chloride, potassium hydroxide, etc. Moreover, Patent Literature 2 describes a liquid tank filled with an organic electrolytic solution of propylene carbonate etc.